Resolution of optical microscopes is limited by diffraction, as explained by the theory of Fourier optics, wherein a resolution limit for a microscope is given by the extent of its optical transfer function, a normalized Fourier transform of a point spread function. For many biological structures and molecular processes, however, their length scale is below a diffraction limit (e.g., a point at which an aperture or opening is too small to allow light to pass through for clear image resolution), preventing them from being resolved with conventional optical microscopes.
The following detailed description of certain embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.